Trammel



March 8, 1949. c. J. o' ROURKE TRAMMEL Original Filed July 7, 1944 V a S \\\\\\\\N INVENTOR. ,CARL J. GROURKE ATTORNE S.

Patented Mar. 8, 1945.

UNITED STATES OFFICE 2,463,796 I ramm- Carl J'. ORo'urke, Mount Vernon, Ohio Original application Jul 7, I944, sen-a1 543,864. Divided a'nd this application June 15,

1945-, Serial No. 599,720

3 Claims. 1.

This invention relates to improvements in trarnmels.

The primary object of this invention is the provision of a trammel of the general nature set forth in my co-pe'nd'ing application Serial Number 543,864, of which the present application is a division.

An object of the present invention is the provision of an improved beam construction for a panel; by means of which the beam may be made of sections connected by an improved joint which will permit of the sliding of the points in adjustment therepast, without interference.

A further object of this invention is the provision of an improved coupling means for trammel beams.

Other objects and advantages of the invention will appear in the renewing detailed description.

In the accompanying drawing forming a part of this specificationand wherein similar reference characters designate corresponding "parts throughout the several views Figure 1 is a side elevation of the improved trammel.

Figure 2 is a fragmentary cross sectional view showing improved means for mounting an extension beam upon the main beam of a trammel or beam compass.

Figure 3 is an end view showing the end structure of the extension beam.

Figure 4 is an end view showing the construction of the end of the main beam which receives the extension beam.

In the drawing, wherein for the purpose of illustration is shown a preferred embodiment of the invention, the letter A may generally designate the improved trammel. It includes a main beam B adapted to receive an extension beam F through an improved coupling structure G. On the beam structure I may employ a point carrying fixture or appliance C and another point appliance D, the same being of the general nature described in detail in my co-pending application above mentioned.

It is the purpose of the present invention to provide a light, durable and economical beam construction with which an extension beam may be used through an accurate straight lined coupling connection. The beam structure is preferably tubular and with the wall thickness just suificient to preserve the desired rigidity thereof.

The point carrying appliance C includes a body portion [5 having a suitable point [6 connected therewith; the body l5 being suitably socketed for sliding. along the entire beam structure, as more specifically described in my above identifled application of which the present application isa division.

The point carrying fixture C includes a body portion and a-.point 63. The body 60 is screw threaded at 10 in an adjusting nut at an end of the beam, the. nut 80 being provided with 'a knurled surface fora Vernier-like adjustment of the point structure -D upon the beam, as has been described in greater detail in my co=pending application above identified.

Referring. to the improved means for mounting an extension beam F upon the main beam B,- the latterat its end opposite the fixture D is open and provided with "a short integral segment 90. best shown in Figures 2 and '4 of the drawing. This den nesa flat surfac 9|.

The extension beam F is tubular and has a mounting plug 9-2-forcefitted or held by means of 'a diametrically disposed pin 93 in an end thereof. The plug- 92 beyond the extreme ehd margin of the extension beam F has an extension 95 of segmental cross section, and of a nature to fit in the opening 91 in the end of the beam B. This segmental extension 95 is provided with a flat surface 9'! adapted to contact the flat surface 9| of the main beam B. With this construction it is obvious that the beams B and F may be connected so as to prevent relative rotation. In order to secure the beams in close abutting relation, and to hold such position, extension portion 95 of the plug 92 is provided with a transverse screw threaded socket 98 adapted to receive an Allen type set screw 99. The latter is rather shallow and bites into the segment to secure the beams B and F in proper alignment. The beam B is provided with a suitable opening 99 to permit of the extension of a screw driver or like tool into the screw threaded passageway 98 for access to the set screw 99.

It will be noted from the drawing that the improved coupling possesses relatively long bearing surfaces so that there will not be any angular misalignment of the two beams, and the segmental connection insures accuracy against rotative turning movement of the beam structures. All parts 'of the connection are such that the beam point C may be slid along the two beams past the connection.

Various changes in the shape, size and arrangement of parts may be made to the form of invention herein shown and described, without departing from the spirit of the invention or the scope of the following claims.

I claim:

1. In a trammel structure the combination of a main beam, an extension beam, said main beam having an end provided with a socket of segmental cross section, the extension beam having a reduced extension thereon of segmental cross section for snug interfitting in said socket of the main beam whereby to prevent relative rotation of said beams, and set screw means transversely adjustably carried by said segmental extension of the extension beam adapted to clamp within the segmental socket of the main beam against the latter to prevent longitudinal detachment of said beams.

2. In a compass beam structure the combination of a pair of beam sections, means upon one of said sections providing a rigidly connected reduced extension at an end thereof of segmental cross section, the other beam at the adjacent end being provided with a socket of segmental cross section for receiving the reduced extension of the first mentioned beam, said beams when so connected having the external surfaces thereof fiush and unobstructed, a set screw transversely adjustable upon said reduced extension, the other beam having an opening for releasably inserting the set screw into said reduced extension in binding engagement against the beam section having the socket for receiving the reduced extension.

3. In a sectional beam structure for compasses the combination of a pair of tubular beams of exactly the same external diameter, one of said beams at an end thereof in the passageway thereof having an elongated segmental projection provided with a flat surface having an indentation therein, the other beam having a plug fixedly inserted in the passageway of the end thereof and having a segmental extension projecting therefrom provided with a chordal fiat surface adapted to fit snugly on the fiat surface of the segmental projection of the first mentioned beam, the segmental extension of the second beam having its external convex surfacing flush with the inner wall of the beam section passageway which supports said extension and adapted to fit snugly against the inner wall of the first mentioned beam section when the segmental extension of said plug is inserted into the passageway of the first mentioned beam section, said segmental extension of the second beam having a transverse threaded passageway therein and the first mentioned beam having a transverse opening which aligns axially with said screw threaded passageway when the beams are assembled, said screw threaded passageway when the beams are assembled with the end edges of the tubular beams abutting axially aligning with the depression in the fiat surface of the segmental projection of the first mentioned beam, and a short set screw threaded into the segmental extension of the second beam and having a tapered end adapted to seat accurately in the depression of the fiat surface of the segmental projection of the first mentioned beam.

CARL J. OROURKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 408,953 Chivill Aug. 13, 1889 473,203 Budke Dec. 15, 1896 626,075 Mock et a1 May 30, 1899 1,678,350 Ott July 24, 1928 2,097,095 Goldfield et al Oct. 26, 1937 FOREIGN PATENTS Number Country Date 101,204 Austria Oct. 10, 1925 611,970 Germany Apr. 11, 1935 846,381 France June 5, 1939 

